Air cooling of engines



Aug. 10, 1943. c. D AN 2,326,335

AIR COOLING 0F ENGINES Filed July 26, 1940 1 2 Sheets-Sheet 1 INVENTOR. WILLIAM C. DEHN @mz. baa

ATTORNEY.

Aug. 10, 1943. w. c. DEHN AIR COOLING OF ENGINES Filed. July 26; 1940 2 Sheets-Sheet 2 FIG.5.

INVENTO-R. WlLLiAM C. DEHN ATTORNEY.

F'IGB.

FIG.'4.

Patented Aug. 10,'1943 f 1 7:: 7':

'lWillia'm CIDehn/EhreeRivers} menin eal;

Fairbanks, Morse Co.

' ration ,of Illinois pplieat on yl iy 26, 19210;: 9 I

This invention relates to improvements in air cooling of engines, and more particularly toan improved air displacing and circulating 'assem- V bly, particularlyadapted for use in cooling the individual cylinders ofirrternal combustion-en'- gines. e s a v z The present developments'were evolved as a result of heretofore prevalent'difficulties in cool ing all parts of each, individualcylinder of 'an air cooled engine, in such manner as toassur'e safe operating temperatures, even in warm climates, and under occasional overload operation; for example, under conditions wherein the errgine is employed for vehicle'p'ro'puls'ion as in the 1 single cylinder engines utilized for the propule sion of railway inspection cars or the like. 7 It is accordingly a major object of the invention to effect a better distribution of cooling air about the cylinder, and a better proportioning of a given Volume of cooling air with respect to the relatively warmer and cooler portions of thecylinder. V I;

An important object of theinventionis at; tained in means conducingto a better and more complete envelopment of the -cylinder by a cooling air stream, together with means for effect ing a substantial turbulence of the air in the cooling air stream immediately adjacent and b,etween the fins of an air cooled engine cylinder.-

Another, object 'of the invention. is attained,

in an improved arrangement fordirecting c oole ing air substantially over the full lengthof a cylinder of a type provided with a series of par: 'allel fins of a trend transverse to the cylinder axis, I I

Yet another object isattainedfin a reversible vehicle-propelling engine, men improved prove sicn of an engine-driven fan,."together with means for supplying a stream of air from the fan to the cylinder or cylinders, in the same manner in either forward or reverse; operation oftheengine, 7 7 Hr; A still furtherobject of the invention-is attained in an improved housing and volute structure which is articularly adapted ito-a reversibly operable, engine-drivenfan, but which is of somewhat general adaptation for use with centrifugal air-irnpelling. agencies of different y .3 i M J V The foregoing and numerous other objects, will more'cle'arly'appear from the, following detailed '7 description of a preferred ,embodirnent of their;-- vention, considered in connection with the; accompanying drawings, inwhich:

' Fig. l is an elevation in perspective of an' en Chicago, 111., a corpo-l e l I gineof" air-cooled .tS'Dej to' which the present im-- provements are applied; Fig; 2 is aside eleva tion of th'e engine, somewhat enlarged, certain portions bein b o n away to illustrate features internally of the assembly; Fig; 3 is a V fragmentaryjhorizontal section as viewed along line 3-4 of-Eig."2;-Fig. 4 is a section in a very ti'cal plane, asjviewedalong line 4 3 of Fig. 2 andFigffi is a fragmentary sectionafview'in a vertical p1ane, 'as taken along line 5-5 of Fig; 2.

'Beferringnow by characters ofreferen'ce to the'drawings of the embodiment selected for de- 'scription, a single cylinder engine designated I generally at ll is provided' with acrankshaft H, crankcase-I 2 and a single air oooled cylin-j f der l3. vTheengine shown isjofatwo -cycle type, which, as-giswell known in the art;.'is readily and inherently reversible in operation, and, in1 ;the, presentexamplereversal of the engine is utilizjedi to effect reverse operation of a railway inspec tion caror the? like (not 'shownil The preferred mounting ofithejengineion the car is sucnthat cylinder;

. in a centrifugal displacementflof'air thereby, so that the flywheel per se, ifunetio'ns asthe' air the cylindenjparticularly the head portion 14 thereof, isfpresented toward thefairfstrearn so as better to realize on themotion of the'fveliicle for coolingpurposes.v

The cooling fin arrangement as. appears on the head l e, consists'of aseries of parallel head fins? I5 while the ribs or fins 16 on the'cylin'der are j preferably'cast integrally therewith and arranged 4 i'n'spaced parallel relation, being'oiannular forni I I H withtheir centers coincident with the axis of the The engine I obvious that the rotation of the flywheel results displacing agency for cooling th e engine.

Surrounding the flywheell' and substantially, enclosing same, is a volute and housing. struc' ture consisting of whatmay be termed a side element 23 seen at theffront of the assembly, and I I a companion side element 24, arranged rearwardly of the flywheel. The housing and v nue structure is conveniently formed at alowcost of fabricated[,sh'eet steel or the like, and is of irregular'curvaturein outline, orin any'event shaped eccentrically with respectt'o' the engine shaft axis." Enclosur'efof the housing and volu'te I structure'jis completed periphera1ly'i,by a mar- I airinlet port v or" fan eyeis I inalband 25:. ndi at n It will be noted from p e 'isf providedvvith a flywheel "2b; hich are a'plurality of spaced, rad y 9, ,,ranged air displacing' blades [2]., I It W111 be:

t e 'diawmts; parti'cu- 7 larly Fig.2, that the volute andfhousing struc- 1 andthe ad tcent fins,

ture is formed to provide-a vol'ute portion which functions, as such, as an air reservoir or build-up space during normal or forward dlrec-, tion of operation of'the engine, and hence of the A second volute portion 3 is similarly provided to function for this purpose during periods in which the engineis operated in reverse direction, the normal-pr forward "direction of engine operation being as infiicated by the arrow ,(Fig. 2). V An outlet duct 32 is providedwhich is characterized, for economy of production, by ra Erectiongular section, which diminishes from the plane 01' connection 33" betweenithe discharge fitting and the volute-housing"lstructurewit will he noted that discharge fitting, 32 connects with direction of engine rotation.

Extending at a right .angle from,; and--.com-

I municating with the '32, is a discharge nozzleefl, the formand structure of which best appears finfFig. 4; .The. member is provided elements 35 and '31 extends between a. pair of the cooling fins i6, so as to provide aipartialsseal between the .sidesof the trough and .thecylinder portion. about, which it is wrapped. This relation isbestrshown by the relationroflthelines indicating the fin outlineLand edge ofsmernlmr 16 m Fi .4:

fBridging siusi'at andfsiuor the nozzle structure, preferably in about the position. shown,

is a'baifie 'member' 'fll'iormedfo'i anlelernent of portionis formed of an open side sheet steel element preferably of a gradually'reduced section from its inlet to its discharge end, and which is assembled to the volute-housing member by a plurality of securely bolted or riveted straps 43.

The duct 42 terminates at its lower or outermost end in a nozzle structure 44, which is generally similar to the nozzle assembly 34, hereto- Ziioreldescribed, except that tor use in certain engines, the side members-cf the-duct ma be eliminated or foreshortened in comparison with. those ii-bl nozzle 34. The nozzle structure 44 is, however, preferably characterized .by the arcuate "trend,and particularly the arcuate bottom portinufi, whichis partlywrapped about the cylin f dercloselyadjacent to the, concentric ribs 46 on the beir'rei portion lfihereof.

both the volute'portions 30 and iii-boas to iunc- '1 tion for the delivery of discharge air, in either sheet-metal, preferablyaluminum Lsheet, even though the nozzle and duct structures 'be' formed of sheetisteel'i i'rh member lli servesa multiple Vpurpo'se as will hereinafter appear, 'andin'keep ing with its function ispreierably disposed in a 1 -c somewhat biasedpositio'n in bridging relation to l the sides36 ands! oiithenozzle structure, The arrangement -'of the' baffle is by preference'at an angle of 30 to a plane normal'to the axis oithe nozzle'troughin" this zone? The depthwise extent of the b'afile or bridge piece l'fl is substantially as 'indicate'din'Fig. 4, namely such that the heme extends .fromifthe bottomelement 38 of'the' nozltisdesirable and preferred that the nozzle 44 he provided with a'bafile element 41, which is or nmyibfisimilar in purpose, extent and location, to the nozzle member heretofore described, except math, is desirably ioc'ated'more ne'arlyexactljyj transverse to the; air streamthroughfthe nozzle 'A slight angularity ortherbaiilet? may -sbe' desirable infengines characterized by a long "stroke and hencealongercylinder. 1

Theoperation of the cooling system hereto fore describedhy reference to-iits 1 parts and as sembly, is thought rto have i been, apparent from the foregoing "discussion, but'rnay bebriefiy re viewed as follows; The rotation of'th'e engine 11ywheehwhich for presentpurposes' may be considered as ablower-or-fan, results during forward through the c'oaction between the'bafile and the ribs or fins on the cylinder, a plurality of divided,

, highly turbulent air strea ms which move out wardly to atmosphere between the ribs or fins of the cylinder, the linear velocitygof *thes'e'streams being substantiallyreduced by reason ofthe turbulence induced therein bybafile "4B. These zle, inwardly or upwardly toproximity with the adjacent cylinder ifins' 16., Only a minor clear ance 'is desirable between the'endof the name Although the air distribution and nozzle arrangement thus 'far'ifdescribed, :i's a1distinctim provment when utilized without further cylinder provisions, it'is preferredtoprovide a spe- 'cific agency for air-cooling the inner "or "barrel portion of the cylinder, "as" distinguished "from'tne headgportion, of the cylinder, and by distinctly directing air streams'over these z onesgthe assembly isarranged so" as substa'rit'idllyto cover the full length'of the cylinderwith a'highly efllcient stream-or streams of 'coolingair. Provision "for cooling the barrel :part -ofjt'ne cylinder'consists, first,' of a port ruin the side volute housing plate 2 1. Thisport-opens' into and'servcs fas air I supply for an elongate, "verticallytdisposed, laterally mounted secondair duct 12. .Th'isiduct streams of air thus 1 advance relatively slowly alongand pastthe'fins or ribs of the cylinder, thusproviding for amaximum heat pickupby the given volume of .air, due to thestated turbulent e'fiect. A considerable part or the streamor cooling air will be lmpelledbetween thebafile dfl and the adjacent fins, andinstead ofbeing given a reversal 'OffflOW by the baiile,will'continu e outwardly through and along the fins 'on'the oppositesideof the cylinder. It results from the provision of thebaffie and the shape "of thenozzle, that the divided streams, being diverted as they are to the 'oppositesides'of the cylinder, result in a highly turbulent series of "streams which practically-envelop, with a highly efficient cooling ac- 1 tion, thehotteror head portion of the cylinder;

Another importantfunction-of the 'baflle 40, due to its angular position, consists in its defleo- 1 tionof an appreciable-part-of the airwhich comes into engagement with "the battle, downwardly or z the head portion andtowardithejbarrel portion.- While it will be understoodthat"a' single nozzle of single width may care for'al l-"of the cylinder of the air to those fins inwardly or downwardly of that cylinder portion which is enveloped by the nozzle 34. t

In the present structure a separate yet cooperating agency consisting of port 41, duct 4-2 and associated nozzle, serves to cool the barrel part of the cylinder in much the same manner as that described above in connection with'nozzle 34 and the head cylinder portion. The course of the air being impelled from port 4! through duct 42 and nozzle 44 is substantially'as above described, and

the efiect of the baille'in nozzle 44 is the same as that of bafile 40, except that because of its dinerent angularity, specifically its lesser bias, it does not so definitely serve to direct a portion of the air stream axially of the cylinder.

Referring now more particularly to the arrangement wherebyspecific provision ismade for effective cooling in reverse operation of the engine, as well as forwardrunning, it will be noted that the radialdisposition of ribs on the flywheel renders it equally efiective asan air displacement agency in either directionof engine rotation. 'I-Iowever, were only a single volute portion provided in the 'fan housing, the blower assembly would be considerably reduced in emciency when running in reverse. Accordingly, ther is providedthe separate volute portion 3| which functions primarily for reverse running. 7

Since, by railroad order, a reverse running of inspection cars and the like is usuallylimited to an scope of the claims hereunto appended.

' The following is claimed: i i V 1. In an air cooling system for} internal combustion .engines, a reversible engine driven fan, a

volute and housing structure about th fan, char-.

acterized by two substantiallyopposite volute portions, an ,end fitting or connection to said housing structure connecting with both volute" portions, aduct communicating with said connections, aside connection laterally secured to and communicating with. the volute-housing structure-a duct communicating with said. side connection, a nozzle for each of said ducts, a tur bulence-inducingbaflle in each of said nozzles, the nozzles being of partly circular trend, and in partly wrapped relation, respectivelyto the head portion and barrel portionof the cylinder, the bafile in the nozzle adjacent the head portion of the cylinder, being arranged in biased relation to thereof,'the cylinder being provided with a plurality of cooling fins respectively on the head and I I on the barrel portion thereof, and coacting with extent of twomiles, and usually at reduced speeds, the provision for cooling air in reverse operationneed not be as great as that for forward running. For this reason the proportion of volume in the forward running volute 30 to the volume in volute 3| is substantially in a ratio of r of partly circulartrend, and in partly wrapped the order of two-thirds and one-third respectively, of the total of the two. It will have ap peared from the description of the volute and fan-assembly that this arrangement is of considspecific purpose, the detail of description herein is to be understood solely in an illustrative, and not in a limiting sense, it being possible with or without minor changes to depart from thev exemthe said battles to produce a divided highly tur-' bulent air stream, and to direct such stream circumferentially of thecylinder.

2. In an air cooling system for internal combustion engines, a reversible engine drivenfan, a volute and housing structure about'th fan, characterized by two substantially opposite volute I portions, a duct, a connection. between said hous-z ing structure and the duct, a nozzle at the outer terminus of the duct, a baflle disposed inzthe nozzle and arranged-substantially across thenormal new of air into the nozzle, the nozzle being relation, to at least a portion of the cylinder, and the bafile being so arranged in the nozzle as to be face-wise impinged by the air stream, whereby to-reverse the direction of and induce a distinct turbulence in a said .portion of the air stream, the baffle being further arranged to permit passage between itselfand the adjacent cylinder, of a portion ofthe air stream; without markedly affecting the direction of the lastsaid portion, the cylinder being provided witha plurality of circumferential cooling finscoacting with the nozzle and with the baflle therein, to direct the several portions of the, air stream i emanating from the nozzle, in directions ferentially of the cylinder. I r

0. been.

circumplary structure without exceeding the spirit and 

